Textile spindle arrangement



April 1, 1969 K. SHOTBOLT TEXTILE SPINDLE ARRANGEMENT,

Filed Jan. 26, 1967 mmvro/e Zf/r 57/075047 -maevm I United States Patent 3,435,604 TEXTILE SPINDLE ARRANGEMENT Keith Shotbolt, Newport, England, assignor to Imperial Chemical Industries Limited, London, England, a corporation of Great Britain Filed Jan. 26, 1967, Ser. No. 611,917 Claims priority, application Great Britain, Feb. 7, 1966, 5,360/ 66 Int. Cl. D01h 7/08, 7/20 US. Cl. 57-134 8 Claims ABSTRACT OF THE DISCLOSURE A spindle mounting for textile winding apparatus having improved vibration characteristics comprising a bearing assembly which engages the main frame at two spaced points through non-oil damped resilient means, the spaced points optionally being positioned so as to minimise spindle tilt.

This invention relates to Winding apparatus for filaments or yarns, and in particular to winding apparatus having a spindle on which the package is formed, or a group of such spindles, being driven by frictional contact of a part thereof with a continuous tape, which tape is driven by a motor, having each spindle rotatably mounted on the main frame of the winding apparatus so as to extend vertically upward from mounting, the tape-engaging part of the spindle being located between the package and the main frame, and having an associated yarn guide, for example a conventional ring and traveller, being reciprocated in a direction parallel to the rotational axis of the spindle.

For convenience in this specification such winding apparatus will be referred to hereinafter as apparatus of the kind specified.

With the present tendency for increased rotational speeds for the spindles of winding apparatus, and for the winding of relatively larger weight packages than heretofore, for productivity reasons, the manner in which the spindles have been mounted on the main frame of the winding apparatus has become increasingly important, and indeed has constituted a major problem inhibiting the attainment of the relatively high spindle speeds desired.

For most winding processes, and in particular for those processes associated with the winding of synthetic polymeric filaments or yarns, it is essential that the lay of the filaments onto the package being wound is in a predetermined manner, such that a stable package is formed (with no tendency for the filament to slough off the package, or the package to disintegrate), and so that there is uniform packing density of the filament within the package.

One source of variation in the manner of lay of the filaments is vibration of the winding apparatus. In addition vibration will cause the spindle mountings to become deformed or worn, causing the performance of the spindles to become erratic.

Generally, each spindle used in apparatus of the kind specified is mounted at an intermediate point and at the foot of the spindle in a journal bearing and a footstep bearing respectively. The latter bearing is generally carried in an insert tube, in a bolster, having a certain amount of flexibility and has associated therewith provision for oil damping. It can be demonstrated that, with spindles of this kind, there usually exists a critical value of the spindle speed when vibration is enhanced. As the speed of such a spindle is increased from zero, vibration increases as this, generally quite low, critical speed is reached and then decreases as the speed is increased further. At relatively high speeds, residual out-of-balance 3,435,604 Patented Apr. 1, 1969 "ice causes high loads at the fixed journal bearing, which loads are transmitted to the machine frame resulting in excessive vibration and noise.

It has been shown that, by providing the journal hearing with a resilient support member, bearing loads can be reduced. The effect of providing such a resilient member is to introduce a second critical speed, this time occurring at a medium speed, but allow smooth running at high speed. Thus, if it is desired to operate at a speed near to the higher critical speed, poor performance can still result. In addition, with this type of spindle, there is a tendency to lose damping oil from the region of the footstep hearing which gives rise to poor performance.

Another disadvantage found with spindles known hitherto is that they may be tilted by engagement with the drive tape, the tilting affecting the way in which the yarn is laid on the package.

According to the present invention in one of its embodiments, winding apparatus of the kind specified includes a mounting for each spindle comprising a bearing assembly which is arranged to engage the main frame of the winding apparatus at two spaced points through non-oil damped resilient means. According to another of the embodiments of the invention, the spindle dimensions are such that the aforesaid two points are positioned with respect to the tape engaging part of the spindle so that spindle tilt is minimised.

In the following discussion, for ease of description, the resilient means comprises two resilient members, although it is to be understood that the invention is by no means limited in this way.

By thus mounting each spindle, then, providing the resilient members have a suitable rebound resilience, vibration at the higher critical speed can be reduced. By providing resilient members having suitable stiffness and by suitable positioning of the resilient members and the bearing assembly, the higher critical speed can be reduced, thus extending the range of speeds suitable for winding, the critical speeds being passed through during start-up procedure, and tilt can be eliminated.

Resiliently deformable plastics materials, such as polyurethanes, are especially useful for forming the resilient members as many of these exhibit suitable rebound resilience. Preferably the materials exhibit rebound resilience less than (Rebound resilience and its measurement are discussed at page 98 of Engineering Design in Rubber by Payne and Scott, published by MacLaren.)

The required degree of stiffness may be conveniently imparted to such resilient members by choice of suitable cross-sectional shape. One such cross-sectional shape that we have found useful is that of a relieved rectangle. By a relieved rectangle in this context We mean a rectangle modified such that two opposite corners are removed leaving a six-sided cross-sectional profile. Preferably each relief commences approximately halfway along each long side and extends at an angle of 10 to the long side.

If the stiffnesses of the resilient members are substantially identical then, to prevent tilt each member should be situated equidistantly from the tape engaging part of the spindle. If the stilfnesses of the resilient members are not substantially identical then, to prevent tilt, each member should be positioned at a different distance from the tape engaging part of the spindle depending on the relative stiffnesses of the two members.

In addition to the bearing assembly and the resilient members, it may be necessary to provide a thrust pad at the base of the spindle, to support the weight of the spindle, and to rovide oil lubrication at this point such that it will lubricate the thrust pad and the bearing assembly. In contrast to hitherto known arrangements, wherein the thrust pad is part of the footstep bearing, in this invention the thrust pad does not need to be flexibly mounted or to be fitted with an expensive and troublesome oil damping arrangement. The present invention enables a shorter bolster to accommodate the spindle below the main frame than would otherwise be required and, since, in this case, the thrust pad will be a shorter distance from a nodal point of vibration, the wear on the thrust pad will be reduced.

One embodiment according to the invention will now be described in greater detail with reference to the accompanying drawing showing a partly sectional elevation of a spindle. A spindle blade is provided with a whorl 11 having a tape engaging Zone 12 and a bobbin housing 13 and is mounted for rotation in a lower bearing 14 and an upper bearing 15, spaced apart by a spacer 16 and located in a bearing housing 17.

Between the spindle blade 10 and the whorl 11 is an upstanding hollow protrusion 18 from a bolster 19, which bolster 19 is fastened to the main frame of a winding apparatus (not shown). The protrusion is spaced apart from the whorl 11 but engages the bearing housing 17 through a lower annular resilient polyurethane member 20 and an upper annular resilient polyurethane member 21, the members 20 and 21 having a relieved rectangular cross-sectional profile such that they both have the same stiffness and being arranged to support the bearing housing 17. The bearing housing 17 and resilient members 20 and 21 are held within the protrusion 18 by a retaining washer 22.

The relative dimensions of the parts are such that the tape engaging zone of the whorl 12 is positioned symmetrically intermediate between the resilient members 20 and 21.

The bearing housing 17 extends into the bolster 18 and a thrust pad 23 is positioned in the lower part of housing 17, into which pad 23 the lower end of the spindle blade 10 sits. The lower part of the bolster 18 is filled with a lubricant 24, which may be drained by removal of a plug 25 in the lower part of the bolster 18.

A brake pad 26 is supported on the bolster 18 such that, on operation of a simple mechanism (not shown), the pad will be forced against the lower end of whorl '11 to slow or stop the spindle when required and a safety device 27 is provided to prevent the spindle whorl 11 from rising too far in operation.

The upstanding protrusion 18 and the bearing housing 17 may be coated with nylon 28 to reduce fretting corrosion between the polyurethanes and the metal surfaces. Alternatively the polyurethane bushes can be bonded to the protrusion and the bearing housing to reduce fertting corrosion.

The construction of the spindle mounting described above in fact constitutes a compromise solution, consideration having been taken of damping the spindle vibra tion, lowering the value of the critical speeds, not allowing the spindle to tilt under belt tension, ensuring that the mounting is adequately lubricated, and providing a construction which is relatively simple in form and easy to manufacture.

What I claim is:

1. In winding apparatus of the kind including a main frame, a vertically extending bolster mounted on the .4 main frame, a footstep bearing and a journal bearing, which journal bearing is contained in bearing housings fitted inside the bolster, a spindle having a lower end mounted for rotation in the bearings and an upper end provided with a bobbin housing and a tape engaging whorl; the improved arrangement wherein the bearing housings are supported within and spaced apart from the bolster by two spaced apart annular resilient members extending round the housings and wherein the tape engaging whorl extends downwardly over the bolster so that it is positioned symmetrically between the annular resilient members.

2. Apparatus according to claim 1 in which the journal bearing consists of two spaced apart bearings.

3. Apparatus as in claim 1 wherein said resilient members have a rebound resilience less than 4. Apparatus as in claim 1 wherein said resilient mem bers are formed of polyurethane.

5. Apparatus as in claim 1 wherein said resilient members in cross section are of rectangular shape relieved on two opposite corners to define a six-sided profile.

6. Apparatus as in claim 5 wherein each relief commences approximately half-way along each long side of the respective rectangle and extends at an angle of 10 to the long side.

7. Winding apparatus comprising: a fixed, verticallyextending, tubular bolster; a vertically-extending, tubular bearing housing disposed in said bolster and radially spaced therefrom; bearing means carried within said bearing housing including a first bearing disposed within the upper portion of said housing, a second bearing disposed at a location spaced below said first bearing, and a nonoil-damped thrust pad disposed in the lower portion of said housing; a spindle mounted for rotation within said bearings and resting on said thrust pad, the upper portion of said spindle projecting out of said bolster; a whorl secured to said upper portion of said spindle and extending downwardly over said bolster, said whorl having a tape-engaging drive surface disposed intermediate said first and second bearings; and two spaced-apart annular resilient members extending around said bearing housing and supporting the latter within said bolster, one of said members being disposed at the level of said first bearing and the other of said members being disposed at the level of said second bearing.

8. Winding apparatus as in claim 7 including means disposed below said second bearing for securing said bolster to a winding apparatus.

References Cited UNITED STATES PATENTS 2,811,824 11/1957 Sweet 57135 XR 2,863,278 12/1958 Scragg 57135 2,969,262 1/1961 Staufert.

3,035,402 5/1962 Westall et al. 57-135 JOHN PETRAKES, Primary Examiner.

U.S. Cl. X.R. 57-135 

